研究者詳細 - 安永　卓生

論文 - 安永　卓生

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3P294 短粒子解析法の高速化のためのGPGPUを用いた並列化処理の実装と評価(27. バイオイメージング,ポスター,第52回日本生物物理学会年会(2014年度)) 査読有り

Iwasaki Ayaka, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 54 ( 1 ) S297 2014年01月

1P295 Metallothionein labeling for CLEM(Correlative Light and Electron Microscopy) method(27. Bioimaging,Poster,The 52nd Annual Meeting of the Biophysical Society of Japan(BSJ2014)) 査読有り

Yamanaka Ryutaro, Hirasaka Yuka, Jin Mingyue, Yanagisawa Haruaki, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 54 ( 1 ) S190 2014年01月

Primary cilia-mediated cellular signaling in dermal papilla cells 査読有り

K Matsushima, M Suematsu, C Mifude, S Aramaki, M Tanaka, T Yasunaga, K Kaseda

JOURNAL OF INVESTIGATIVE DERMATOLOGY 133 ( 5 ) 1407 - 1407 2013年05月

Kinesin-1 regulates dendrite microtubule polarity in Caenorhabditis elegans 査読有り国際誌

Jing Yan, Dan L Chao, Shiori Toba, Kotaro Koyasako, Takuo Yasunaga, Shinji Hirotsune, Kang Shen

eLife ( eLife Sciences Publications, Ltd ) 2 e00133 2013年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

<jats:p>In neurons, microtubules (MTs) span the length of both axons and dendrites, and the molecular motors use these intracellular ‘highways' to transport diverse cargo to the appropriate subcellular locations. Whereas axonal MTs are organized such that the plus-end is oriented out from the cell body, dendrites exhibit a mixed MTs polarity containing both minus-end-out and plus-end-out MTs. The molecular mechanisms underlying this differential organization, as well as its functional significance, are unknown. Here, we show that kinesin-1 is critical in establishing the characteristic minus-end-out MT organization of the dendrite in vivo. In unc-116 (kinesin-1/kinesin heavy chain) mutants, the dendritic MTs adopt an axonal-like plus-end-out organization. Kinesin-1 protein is able to cross-link anti-paralleled MTs in vitro. We propose that kinesin-1 regulates the dendrite MT polarity through directly gliding the plus-end-out MTs out of the dendrite using both the motor domain and the C-terminal MT-binding domain.</jats:p>

DOI： 10.7554/elife.00133

CiNii Research

その他リンク： https://cdn.elifesciences.org/articles/00133/elife-00133-v1.pdf

生体分子の電子顕微鏡法による 3 次元再構成法

安永卓生, 我妻竜三

顕微鏡 ( 日本顕微鏡学会 ) 47 ( 2 ) 110 - 117 2012年06月

Tilt-angle measurement of a sample stage using a capacitive liquid-based inclinometer 査読有り

Kyoko Matoba, Junichi Takagi, Takuo Yasunaga, Hiroshi Jinnai, Kenji Iwasaki

Microscopy 61 ( 3 ) 193 - 198 2012年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

Alignment of projection images in tomographic reconstruction is a critical process that governs the quality of the reconstructed three-dimensional (3D) image. The most popular alignment method is the marker-based alignment, which typically uses colloidal gold particles added to the specimen (called fiducial markers) to calculate the coordinates of each projection image in the tilt series. This method, however, is not effective when each image contains only a small number of fiducial markers. Therefore, of all the parameters required for alignment, we focussed on the tilt angle and attempted to gage it directly in order to examine whether the acquired angle is accurate enough to perform tomographic reconstruction. We showed that the tilt angle measured using a commercially available capacitive liquid-based inclinometer is more precise than the reading from the monitor of the electron microscope and that it can lead to 3D reconstructions of quality similar to those obtained by the marker-based alignment method. The Author 2012. Published by Oxford University Press [on behalf of Japanese Society of Microscopy]. All rights reserved.

DOI： 10.1093/jmicro/dfs034

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84862898328&origin=inward

Enhanced detection efficiency of genetically encoded tag allows the visualization of monomeric proteins by electron microscopy 査読有り

Yuko Fukunaga, Ai Higashihara, Yuri Nishino, Takuo Yasunaga, Mingyue Jin, Atsuo Miyazawa

Journal of Electron Microscopy 61 ( 4 ) 229 - 236 2012年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

A cadmium-binding, genetically encoded protein tag, consisting of three repeats of metallothionein (3MT), can be used in electron microscopy for the visualization of multimeric- but not monomeric-tagged proteins due to insufficient electron density in monomeric proteins. Here, we present a technique for detecting monomeric 3MT-tagged green fluorescent protein (GFP-3MT) using a platinum compound to intensify the electron density. Substitution of cadmium by platinum as a result of incubating purified cadmium-binding 3MT-tagged GFP (GFP-Cd-3MT) with cis-diamminedichloroplatinum(II) (cisDDP) was assessed by a UV absorption band centered at 284 nm thereby indicating platinum-sulfhydryl bonds. The incubation time and the concentration of cisDDP to reach maximal absorption were 2 h and 36-fold molar equivalent of cisDDP, respectively. GFP-Pt-3MT isolated by gel filtration chromatography contained 29 platinum atoms per single GFP-3MT molecule. Electron-dense particles were observed in a GFP-Pt-3MT sample by electron microscopy without negative staining. Further image processing and image analysis demonstrated that particles with higher density relative to their surroundings were detectable in both GFP-Cd-3MT and GFP-Pt-3MT samples. These results demonstrate that replacement of cadmium with platinum, together with proper image analyses, improve detection efficiency and enable the visualization of 3MT-tagged monomeric protein by electron microscopy. © 2012 The Author. Published by Oxford University Press.

DOI： 10.1093/jmicro/dfs043

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84864976128&origin=inward

1PT185 拘束付き分子動力学法を適用した、電子顕微鏡法のための原子モデル構築ツールの開発(日本生物物理学会第50回年会(2012年度))

Yamashita Risa, Nakao Ryota, Sakamoto Hiroshi, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 52 ( supplement ) S100 2012年01月

StHsp14.0, a small heat shock protein of Sulfolobus tokodaii strain 7, protects denatured proteins from aggregation in the partially dissociated conformation 査読有り

Abe T., Oka T., Nakagome A., Tsukada Y., Yasunaga T., Yohda M.

JOURNAL OF BIOCHEMISTRY 150 ( 4 ) 403 - 409 2011年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

The small heat shock protein (sHsp), categorized into a class of molecular chaperones, binds and stabilizes denatured proteins for the purpose of preventing aggregation. The sHsps undergo transition between different oligomeric states to control their nature. We have been studying the function of sHsp of Sulfolobus tokodaii, StHsp14.0. StHsp14.0 exists as 24meric oligomer, and exhibits oligomer dissociation and molecular chaperone activity over 80°C. We constructed and characterized StHsp14.0 mutants with replacement of the C-terminal IKI to WKW, IKF, FKI and FKF. All mutant complexes dissociated into dimers at 50°C. Among them, StHsp14.0FKF is almost completely dissociated, probably to dimers. All mutants protected citrate synthase (CS) from thermal aggregation at 50°C. But, the activity of StHsp14.0FKF was the lowest. Then, we examined the complexes of StHsp14.0 mutants with denatured CS by SAXS. StHsp14.0WKW protects denatured CS by forming the globular complexes of 24 subunits and a substrate. StHsp14.0FKF also formed similar complex but the number of subunits in the complex is a little smaller. These results suggest that the dimer itself exhibits low chaperone activity, and a partially dissociated oligomer of StHsp14.0 protects a denatured protein from interacting with other molecules by surrounding it. © 2011 The Authors. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

DOI： 10.1093/jb/mvr074

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=80053558864&origin=inward

1G1312 3D structure of the 26S proteasome by high-resolution electron cryo-microscopy(Protein: Structure 1,The 49th Annual Meeting of the Biophysical Society of Japan)

Okuma Yasuo, Kasuya Daisuke, Mitsuoka Kaoru, Saeki Yasushi, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 51 ( 0 ) S45 2011年01月

1G1424 冷陰極電界放出銃を用いた、クライオ電子顕微鏡法による小さい生体分子複合体構造解析への挑戦(蛋白質_構造 1,第49回日本生物物理学会年会)

Watanabe Keita, Ogawa Kaori, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 51 ( 0 ) S46 2011年01月

Structure and Function of Small Heat Shock Proteins from the Magnetotactic Bacterium Magnetospirillum magneticum AMB-1 査読有り

Abe T, Ito S, Nishi N, Tsukada Y, Yasunaga T, Araki A, Matsunaga T, Yohda M,

KOBUNSHI RONBUNSHU ( 公益社団法人高分子学会 ) 67 ( 12 ) 698 - 704 2010年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

スモールヒートショックプロテイン(sHsp)は通常の温度条件下では分子量 12-43 kDa のサブユニットが大きな複合体を形成しているが，熱ストレス下においてはその構造が可逆的に解離する．この解離が sHsp の機能発現に重要な役割をもつと考えられている．磁性細菌 <i>Magnetospirillum magneticum</i> AMB-1 には sHsp とアミノ酸配列の相同性がある ORF が三つ存在した(YP_423206，YP_423303，YP_421578)．分子量からそれぞれ，Hsp17.8, Hsp17.5, Hsp18.3 と命名し大腸菌により大量発現させ精製した．それぞれ，モデル基質である豚心臓由来クエン酸合成酵素の凝集を抑制し，分子シャペロンとして機能していることが明らかとなった．また，ゲルろ過クロマトグラフィーや電子顕微鏡観察により Hsp17.8 はこれまでに報告のある球状のオリゴマーを形成し，Hsp17.5，Hsp18.3 は興味深いことに，巨大なフィラメント構造を形成していた．これまでにも，sHsp がフィラメント構造を形成する報告はあるものの，タンパク質の凝集抑制能を有するものとしては，初めての例である．<br>

DOI： 10.1295/koron.67.698

Scopus

CiNii Article

CiNii Research

Structural Basis for Actin Assembly, Activation of ATP Hydrolysis, and Delayed Phosphate Release 査読有り

Murakami K., Yasunaga T., Noguchi TQP, Gomibuchi Y., Ngo KX, Uyeda TQP, Wakabayashi T.

CELL 143 ( 2 ) 275 - 287 2010年10月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Assembled actin filaments support cellular signaling, intracellular trafficking, and cytokinesis. ATP hydrolysis triggered by actin assembly provides the structural cues for filament turnover in vivo. Here, we present the cryo-electron microscopic (cryo-EM) structure of filamentous actin (F-actin) in the presence of phosphate, with the visualization of some α-helical backbones and large side chains. A complete atomic model based on the EM map identified intermolecular interactions mediated by bound magnesium and phosphate ions. Comparison of the F-actin model with G-actin monomer crystal structures reveals a critical role for bending of the conserved proline-rich loop in triggering phosphate release following ATP hydrolysis. Crystal structures of G-actin show that mutations in this loop trap the catalytic site in two intermediate states of the ATPase cycle. The combined structural information allows us to propose a detailed molecular mechanism for the biochemical events, including actin polymerization and ATPase activation, critical for actin filament dynamics. © 2010 Elsevier Inc.

DOI： 10.1016/j.cell.2010.09.034

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77957793677&origin=inward

Three Outer Arm Dynein Heavy Chains of Chlamydomonas reinhardtii Operate in a Coordinated Fashion Both In Vitro and In Vivo 査読有り

Takazaki H, Liu ZM, Jin MY, Kamiya R, Yasunaga T

CYTOSKELETON 67 ( 7 ) 466 - 476 2010年07月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Outer arm dynein (OAD) in cilia and flagella contains two to three nonidentical heavy chains (HCs) that possess motor activity. In Chlamydomonas, flagellar OAD contains three HCs, a-, b-, and c-HCs, each appearing to have a distinct role. To determine the precise molecular mechanism of their function, cross-sectional electron micrographs of wild-type and single HC-disruption mutants were compared and statistically analyzed. While the a-HC mutant displayed an OAD of lower density, which was attributed to a lack of a-HC, the OAD of band c-HC mutants not only lacked the corresponding HC, but was also significantly affected in its structure, particularly with respect to the localization of a-HC. The lack of b-HC induced mislocalization of a-HC, while a disruption of the c-HC gene resulted in the synchronized movement of a-HC and b-HC in the manners for stacking. Interestingly, using cryo-electron microscopy, purified OADs were typically observed consisting of two stacked heads and an independent single head, which presumably corresponded to c-HC. This conformation is different from previous reports in which the three HCs displayed a stacked form in flagella observed by cryo-electron tomography and a bouquet structure on mica in deep-etch replica images. These results suggest that c-HC supports the tight stacking arrangement of inter or intra a-/b-HC to facilitate the proper functioning of OAD. © 2010 Wiley-Liss, Inc.

DOI： 10.1002/cm.20459

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77955867545&origin=inward

1P150 1D1435 アクチン重合とそれに伴うATPase活性化の構造的基盤(筋肉(筋蛋白質・収縮),口頭発表,第48回日本生物物理学会年会)

Murakami Kenji, Yasunaga Takuo, Noguchi Taro, Gomibuchi Yuki, Ngo Kien, Uyeda Taro, Wakabayashi Takeyuki

生物物理 ( 一般社団法人日本生物物理学会 ) 50 ( supplement2 ) S45 - S46 2010年01月

1P325 小さい生体分子複合体のためのクライオ電子顕微鏡法の挑戦(バイオイメージング,第48回日本生物物理学会年会)

Watanabe Keita, Ogawa Kaori, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 50 ( supplement2 ) S77 2010年01月

1P166 クラミドモナスの外腕ダイニンが持つ構造特徴(分子モーター,第48回日本生物物理学会年会)

Takazaki Hiroko, Jin Mingyue, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 50 ( supplement2 ) S48 2010年01月

1P168 クライオ電子顕微鏡法による車軸藻ミオシンの高速移動分子メカニズムの解明(分子モーター,第48回日本生物物理学会年会)

Hidaka Hiroaki, Mine Hiroshi, Ito Kohji, Yamamoto Keiichi, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 50 ( supplement2 ) S49 2010年01月

1P153 硬直状態におけるアクチン-ミオシン硬直複合体の三次元構造(筋肉(筋蛋白質・収縮),第48回日本生物物理学会年会)

Tsukada Yoshihiro, Wakabayashi Takeyuki, Yasunaga Takuo

生物物理 ( 一般社団法人日本生物物理学会 ) 50 ( supplement2 ) S46 2010年01月

Dynein pulls microtubules without rotating its stalk 査読有り国際誌

Ueno H., Yasunaga T., Shingyoji C., Yamaguchi T., Hirose K.

Proceedings of the ASME Summer Bioengineering Conference 2009, SBC2009 ( PART A ) 555 - 556 2009年12月

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